My work in the areas of occupational and environmental health and safety grew out of research on pesticides and is closely related to my work on risk assessment and communication and food safety.

Some research highlights in this area are:

Research Results

References

The methods scientific and technical experts have developed for constructing quantitative assessments of health and safety risks have major shortcomings as tools for decision analysis. We use a model of cost effective risk management under uncertainty to discuss shortcomings of standard risk assessment methods as decision support aids, including problems of comparability of risk estimates and costs of saving statistical lives from compounded conservatism and lack of flexibility in modeling regulatory intervention. Offsets and risk shifting due to regulation-induced changes in firm and household behavior show that risk assessments need to incorporate economic and behavioral science models. Empirical studies demonstrate that the tools of economic analysis can help risk assessments generate much richer information sets both at the overarching level of embedding risk assessments in decision theoretic frameworks for risk management decisions and at the internal level by giving risk assessments the capacity to capture the effects of behavioral changes on risk.

Prevention is not always more cost effective and precautionary than ex post treatment. A greater degree of precaution can result in less reliance on prevention. An empirical case study indicates that treatment alone is the most cost effective means of dealing with nitrate in most Maryland community water system wells. The incremental cost of precaution is substantial.

Growers who have experienced adverse health effects from pesticides (either directly or indirectly) have heightened concern about environmental and occupational safety problems arising from pesticide use and are more likely to use certain non-chemical control practices.

Regulations preventing farm workers from entering fields for a specified period of time after pesticides have been sprayed may be an incentive for farmers to spray preventively rather than reactively. An empirical analysis of preharvest intervals in U.S. apple production suggests that current EPA regulations may not have been protective enough. Also, flexible regulations that allow preharvest intervals to vary according to rainfall or other obervable indicators of risk can provide the same or greater levels of protection to farm workers at lower cost.

Lichtenberg, Erik, Robert C. Spear and David Zilberman, "The Economics of Re-Entry Regulation of Pesticides", American Journal of Agricultural Economics 75, 946-958 (November 1993).

EPA's use of safety factors to adjust for uncertainty distorts regulatory decision making by inflating risk estimates, by making risk estimates statistically non-comparable (so that they can't be used for cost effectiveness analysis), by making bans preferable to phaseouts, and by placing too much weight on low-risk, high-uncertainty problems (e.g., pesticide residues on foods) and too little on higher-risk, lower-uncertainty problems (e.g., farmworker safety)..

The standard sanitary engineering/public health approach to handling uncertainty about health risks derives from a classical statistics approach involving the use of the upper tail of a confidence interval with a high degree of significance (margin of safety). Under least-cost regulation, a higher margin of safety means higher total cost but lower marginal cost and may lead regulators to emphasize uncertainty reduction (e.g., through data collection) at the expense of reductions in risk on average. Empirical studies of pesticide contamination of drinking well water and shellfish contamination by dairy wastes show that the incremental cost of increasing the margin of safety can be quite high.